<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style media="screen">
        .tableA {
            border-collapse: collapse;
            color: #f00
        }

        .tableA .title th {
            height: 50px;
            font-size: 24px;
            font-family: '微软雅黑';
            font-weight: 700;
        }

        .tableA tr th {
            border: 1px #000 solid;
            height: 40px;
            background: #efefef;
        }

        .tableA tr td {
            padding: 0 40px;
            border: 1px #000 solid;
            height: 40px;
            text-align: center;
        }

        .tableA .footer td {
            font-size: 20px;
            font-weight: 700;
        }
    </style>
</head>

<body>
    <table bordercolor="black" class="tableA">
        <tr class="title">
            <th colspan="4">学生信息</th>
        </tr>
        <tr>
            <th>名字</th>
            <th>性别</th>
            <th>年龄</th>
            <th>班级</th>
        </tr>
        <tr>
            <td>小明</td>
            <td>男</td>
            <td>19</td>
            <td>1班</td>
        </tr>
        <tr>
            <td>小黄</td>
            <td>男</td>
            <td>20</td>
            <td>2班</td>
        </tr>
        <tr>
            <td>老王</td>
            <td>男</td>
            <td>29</td>
            <td>3班</td>
        </tr>
        <tr class="footer">
            <td colspan="4">总人数：3人</td>
        </tr>
    </table>
    <button onclick="deriveAble()">导出表单</button>
    <script>
        var oHtml = document.getElementsByClassName('tableA')[0].outerHTML;
      
        function deriveAble() {
            var excelHtml = `
    <html>
      <head>
        <meta charset='utf-8' />
        <style>
          .tableA {
            border-collapse: collapse;
          }
          .tableA .title th{
            height: 50px;
            font-size: 24px;
            font-family: '微软雅黑';
            font-weight: 700;
          }
          .tableA tr th {
            border: 1px #000 solid;
            height: 40px;
            background: #efefef;
          }
          .tableA tr td {
            padding: 0 40px;
            border: 1px #000 solid;
            height: 40px;
            text-align: center;
          }
          .tableA .footer td {
            font-size: 20px;
            font-weight: 700;
          }
        </style>
      </head>
      <body>
        ${oHtml}
      </body>
    </html>
  `
            var excelBlob = new Blob([excelHtml], { type: 'application/vnd.ms-excel' })
            // 创建一个a标签
            var oA = document.createElement('a');
            // 利用URL.createObjectURL()方法为a元素生成blob URL
            oA.href = URL.createObjectURL(excelBlob);
            // 给文件命名
            oA.download = '学生名单.xls';
            // 模拟点击
            oA.click();

        }

    </script>
</body>

</html>